A valve timing controller includes a first rotary element rotating in response to one of a crankshaft and a camshaft and a second rotary element rotating in response to the other of the crankshaft and the camshaft. The controller changes a relative rotation phase between the rotary elements by a link mechanism to adjust valve timing.
Specifically, in a device disclosed in JP-2005-48707A (U.S. Pat. No. 6,883,482 B2), a link mechanism that is constituted by combining a first link linked to a first rotary element and a second link linked to a second rotary element and the first link is provided in the first rotary element. Here, the first link is linked to the first rotary element by a revolute pair via a shaft fitted therein and the second link is linked to the second rotary element and the first link by a revolute pair via the shaft fitted therein.
In general, a valve timing controller is operated in response to momentarily changing operational states of an internal combustion engine, and therefore, the operation frequency thereof is higher. Because of that, in the device disclosed in JP-2005-48707A, when each link of a link mechanism is relatively rotated with respect to the shaft, there is a concern that wear is generated in an interface between each link and the shaft, so that the durability is deteriorated. Then, a method to introduce a lubricating fluid into the first rotary element receiving the link mechanism for reducing wear can be considered, but only with the introduction of the lubricating fluid into the rotary element, it is difficult to provide the lubricating fluid to a pinpoint, that is, the interface between each link and the shaft in the link mechanism of which the operation frequency is higher.